Although many socialization agents influence children"s behavior (D. L. Vandell; see record 2000-00919-001), the evidence (e.g., from intervention studies) indicates that each exerts its influence only within its own domain. Context effects and genetic effects are among the confounding factors that make it impossible, given current data, to reject the null hypothesis of zero long-term effects of parenting on child outcomes. Problems with the prevailing view of development cannot be solved by invoking within-home environmental differences or gene-environment interactions. Group socialization theory can account for findings that do not fit the prevailing view. The theory attributes outside-the-home socialization to identification with a peer group and assimilation of group norms, but attributes nongenetic variation in personality to differentiation within the group. The latter proposition is still largely untested but other aspects of the theory are well supported by evidence